Elasticity

Price Elasticity of Demand

The price elasticity of demand measures how much the quantity demanded of a good responds to a change in its price. It is a key concept in microeconomics, helping to analyze consumer behavior and market dynamics.

• Definition: Price elasticity of demand is the percentage change in quantity demanded divided by the percentage change in price.

• Formula:

• Interpretation: Elasticity shows how sensitive consumers are to price changes. A higher absolute value indicates greater sensitivity.

Calculating Price Elasticity of Demand

To calculate price elasticity, follow these steps:

1. Identify the initial and new prices and quantities demanded.

2. Calculate the percentage change in quantity demanded:

3. Calculate the percentage change in price:

4. Divide the percentage change in quantity demanded by the percentage change in price.

Example Calculation:

• If the price of a good rises from $10 to $12 and the quantity demanded falls from 20 units to 16 units:

• Average price =

• Average quantity =

• Percentage change in price =

• Percentage change in quantity demanded =

• Price elasticity of demand =

Note: The negative sign indicates the inverse relationship between price and quantity demanded. For comparison, use the absolute value.

Interpreting Elasticity Values

• Elastic Demand: (Quantity demanded changes more than price)

• Inelastic Demand: (Quantity demanded changes less than price)

• Unit Elastic: (Quantity demanded changes exactly as much as price)

Midpoint (Arc) Method

The midpoint method uses averages to calculate percentage changes, providing a more accurate measure of elasticity over a range of prices and quantities.

• Formula:

• This method avoids the problem of different elasticity values depending on the direction of change.

Summary Table: Elasticity Classification

Applications and Importance

• Helps businesses set prices to maximize revenue.

• Informs government policy on taxation and subsidies.

• Assists in understanding consumer behavior and market efficiency.

Additional info: The notes infer the use of the midpoint method and the importance of using absolute values for elasticity comparisons, which are standard in microeconomics.